1. Field of the Invention
The present invention relates to an image forming apparatus utilizing an electrophotographic process.
2. Related Background Art
In a color image forming apparatus utilizing an electrophotographic process, there is known an apparatus utilizing an intermediate transfer method in which a toner image formed on a photosensitive drum is once transferred onto an intermediate transfer member, and plural toner images superposed on the intermediate transfer member are collectively secondarily transferred onto a transfer material.
Also, for recovering so-called transfer residual toner (also called “secondary transfer residual toner”) remaining on the intermediate transfer member after the transfer of the toner images therefrom onto the transfer material, there is known a method of charging the secondary transfer residual toner in a polarity opposite to that of the toner by a roller member or the like opposed to the intermediate transfer member, and returning the secondary transfer residual toner by transfer thereof onto the photosensitive drum while executing primary transfer of the toner image from the photosensitive drum.
However, the aforementioned method of returning the secondary transfer residual toner onto the photosensitive drum has a drawback that a part of the secondary transfer residual toner is deposited (adhered) on the roller member for charging such secondary transfer residual toner in the polarity opposite to that of the toner, and such roller member becomes incapable of charging the secondary transfer residual toner in the desired polarity, depending on the amount of such deposition (adherence).